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Brugada syndrome.
20 years of progress.
Genetic background
„Right bundle-branch block, persistent ST-segment elevation in the right precordial leads and sudden cardiac death: a distinct clinical and electrocardiographic syndrome“
J Am Coll Cardiol 1992;20:1391
Brugada P, Brugada J. 1992:
„ECG abnormalities constitute the hallmark of Brugada syndrome.
They include repolarization and depolarization abnormalities
in the absence of identifiable structural cardiac abnormalities
or other conditions or agents known to lead to ST-segment elevation
in the right precordial leads“
Circulation 2002;106:2514
ST- segment elevation
P wave duration ↑
QRS prolongation, RBBB and LFHB
QT prolongation / QT shortening.
Atrial arrhythmias
Ventricular arrhythmias
SN dysfunction
PR prolongation
Late potentials (SAECG)
Repolarization abnormality
Conduction defect and depolarization abnormality
J wave accentuation
→ „Spontaneous coved ST-segment elevation is a marker of malignant ventricular arrhythmias and sudden cardiac death“
→ Right bundle-branch block
Variability of the diagnostic ECG pattern
→ 35% of patients diagnosed with Brugada syndrome do not reveal a spontaneous coved-type ECG during 4-years follow-up
→ Transient normalization and/or conversion to saddleback-type pattern occur in > 95% of the patients during long-term follow-up
Eur Heart J 2006;27:593
→ Only every 4th ECG is spontaneously diagnostic and every 2nd ECG does not display any Brugada-type ST elevation
Feb5 Feb7 Feb13
Diagnostic tools to unmask a type I ECG pattern
→ Superior placement of the right precordial leads
→ ECG monitoring during recovery phase of exercise
→ Administration of a class I sodium channel blocker
Class I drug Dosage
Ajmaline 1 mg/kg over 5 min, IV
Flecainide 2 mg/kg over 10 min, IV
Procainamide 10 mg/kg over 10 min, IV
Pilsicainide 1 mg/kg over 10 min, IV
→ diagnosis of individuals with normalized or non-diagnostic ECG
→ identification of family members at risk for the disease
Class I drugs to unmask Brugada syndrome
ajmaline IV
Ajmaline test in children
pre post pre post
Flecainide test in overt Brugada syndrome
baseline flecainide
affected family member non-affected family member
SCN5Amt SCN5Awt
Sens 80.0%
Spec 94.4%
PPV 93.3%
NPV 82.9%
Am J Cardiol 2007;99:53
Cardiovasc Res 2005;67:367
ST-segment elevation in lead aVL
ajmaline IV
after ajmaline IV
after ajmaline IV
→ “Aizawa pattern“ , 1996 I
II
V1
J
I
II
V1
Ajmaline IV
Accentuation of the J wave
I
II
V1
Lidocaine IV
Electrical cardioversion
→ Conduction abnormalities in myotonic dystrophy type I
baseline ajmaline PACE 1999;22:1264
Pectus excavatum Mediastinal tumor
Conduction abnormalities
J Am Coll Cardiol 2002;40:350
HV 66±13 HV 48±9 PQ 209±51 PQ 163±24
PR 270 ms
sinoatrial conduction time ↑
slowed atrial conduction
atrial standstill
infrahisian conduction delay
→ SA block II°, cSNRT ↑
→ P-wave duration ↑, PR ↑
→ SA block III°
→ PR ↑, QRS duration ↑, RBBB, LFHB
→ most frequently observed in patients linked to SCN5A mutations
Overlap syndromes
Long-QT 3 Familial conduction disease (Lev-Lenègre disease)
Circ Res 1999;85:1206 Circulation 2001;104:3081
→ Incidence up to 20%, particularly paroxysmal AFib and AFlutter
→ First manifestation of Brugada syndrome
→ Common cause of frequent inappropriate ICD shocks
Atrial arrhythmias
Polymorphic ventricular tachycardia and VF
Monomorphic ventricular tachycardia
→ rare in Brugada syndrome
Fragmented QRS in Brugada syndrome
Fragmented QRS in Brugada syndrome
Fragmented QRS in Brugada syndrome
Fragmented QRS in Brugada syndrome
Proposed pathophysiological mechanisms of Brugada syndrome.
Slow conduction Repolarization abnormality Development abnormality
J Cardiovasc Electrophysiol 2001;12:268 Cardiovasc Res 2005;67:367 Heart Rhythm 2007;4:359
Coved-type I ECG spontaneously or after class I AAD
asymptomatic aborted SCD or syncope
ICD
spontaneous coved-type ECG
+ -
EP study
Follow-up
+ -
Follow-up ICD
Management of patients with Brugada syndrome
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